This invention relates to improvements to a rising bubble display device of the type having a reservoir which contains a liquid, a conduit positioned near one end of the reservoir which defines an array of orifices, a pump coupled to the conduit to introduce bubbles of a fluid into the reservoir via the orifices such that the bubbles of fluid move upwardly in the reservoir, and a lamp positioned to illuminate the bubbles of fluid in the reservoir.
The assignee of the present invention has marketed a rising bubble display device of the type described above for some years under the trade name "Water Panel." This prior art Water Panel display utilizes a ten gallon reservoir which weighs over eighty pounds when filled. The reservoir is mounted via channels to stand vertically above a base, and the reservoir defines an array of vertical cells extending upwardly from the base. A fluorescent lamp is positioned vertically above the reservoir to illuminate the upper surface of the reservoir, and an air pump forces air through orifices in a conduit positioned at the base of the reservoir. A clear plastic strip is fixed in place between the lamp and the upper surface of the reservoir.
The Water Panel display has achieved considerable success. Nevertheless, there are certain drawbacks to this device. First, the Water Panel display is essentially factory built, and it is difficult or even impossible for a user to alter or service certain features of this display. For example, it is not possible for the user to change the color of the illuminating light. Furthermore, the orifice defining tube is fixed in the base of the reservoir. On occasion individual orifices may become clogged, and it was in the past difficult or impossible for a user to unclog the individual orifices.
Second, the Water Panel display is not readily serviced by some users. In particular, because of the weight of the reservoir when filled, it generally is not advisable for the user to lift the filled reservoir out of the base (even though this is technically possible) in order to empty reservoir. The Water Panel display does include a check valve interposed between the pump and the reservoir in order to prevent liquid from reaching the pump.
Third, the Water Panel display is relatively expensive to manufacture. In particular, the cells in the reservoir are defined by transverse ribs, each of which defines a notch positioned to receive the orifice defining conduit. This results in a relatively complex mechanical assembly which requires considerable labor to manufacture.
It is accordingly an object of this invention to provide a rising bubble display device of the general type described above which is more readily serviced, more readily repaired, more readily customized by the end user and more readily manufactured.